First it was his long game going downhill.He couldn't hit a fairway any better than a drunken foursome on a weekend.
Next up,was his short game.Him and his caddie would ponder over and over which club was the right 1,and he would either come up short or overshoot the green.
Lastly,his putting.This is a part of his game which did not go in the toilet dramatically,as it was always just at average or a little above for the tour.
A few hours at the mini-putt could have helped him here.
You can change swing coach's and caddies numerous times to no avail.
IMO he lost and never regained his confidence in his game.